JP2020089261A - Insulation body for electrical machine - Google Patents

Abstract

To provide improved embodiments for an electrical machine characterized by improved cooling of stator winding in a stator.SOLUTION: An insulation body (100) comprises outer walls (101a, 101b, 101c, and 101d) composed of a plastic (11), which defines a body interior (104). At least one winding zone (106a and 106b) for receiving a stator winding and at least one channel zone (107a and 107b) for receiving a cooling channel are provided in the body interior (104).EFFECT: Cooling of a stator winding can be improved without generating electrical short circuit between the stator winding and teeth.SELECTED DRAWING: Figure 1

Description

The present invention relates to electric machines, and more particularly to electric machines for motor vehicles that include insulating objects. The invention also relates to a motor vehicle including such an electric machine.

This type of electric machine may generally be an electric motor or a generator. This electric machine may be realized as an outer rotor or an inner rotor.

A general type of electric machine is known, for example, from Patent Document 1 below. This electric machine includes a housing that surrounds the inside, the housing extending to the outer circumference in the outer peripheral direction and limiting the inside to the radial direction, and a rear part that limits the inside to the axial direction in one axial direction. It has a side wall and a front side wall that axially limits the interior in the other axial direction. The stator of the electric machine is fixedly connected to the case. A rotor of the electric machine is arranged in a stator, and a rotor shaft of the rotor is rotatably mounted on a front side wall by a front bearing.

The stator of a conventional electric machine typically includes a stator winding to which a voltage is applied during operation of the electric machine. This results in heat that must be dissipated in order to avoid overheating and the associated damage, and even damage to the stator. Therefore, it is known that the conventional electric machine is provided with a cooling device for cooling the stator, particularly for cooling the stator winding. Such a cooling device circulates a coolant and is provided in the vicinity of a stator winding in the stator, typically in a status lot, that is, in the outer circumferential direction of the stator which also accommodates the stator winding. It includes one or more cooling passages disposed in the intermediate space between the stator teeth. The transfer of heat from the stator windings to the coolant allows the heat to dissipate from the stator.

US Pat. No. 5,214,325

In this case, it proves to be a disadvantage that efficient heat transfer from the stator to the coolant flowing through the individual cooling channels can only be realized with undeniable structural complexity. However, this has a negative effect on the manufacturing costs in electric machines.

Furthermore, in the case of conventional electric machines, undesired electrical short circuits between the stator windings and the coolant flowing through the cooling flow path and between the stator windings and the stator teeth of the stator (hereinafter simply referred to as short circuits). Call)) can prove to be a problem under certain circumstances. This situation means that the insulation of the windings in the stator winding is damaged, for example by manufacturing or during the assembly process, and after the stator winding is introduced into the intermediate space, the stator winding is, for example, assembled. It is the situation such as touching the cooling channel, coolant or stator teeth.

Therefore, it is an object of the present invention to provide an improved embodiment of the electric machine so that this disadvantage is large and even eliminated altogether. In particular, the object is to provide an improved embodiment for an electric machine characterized by improved cooling of the stator windings in the stator.

This object is achieved by the subject matter of the independent claims. The dependent claims relate to preferred embodiments.

It is therefore an object of the present invention to provide an electrically insulating body which can be inserted as a prefabricated structural unit (prefabricated unit) in the intermediate space between two stator teeth in an electric machine stator (so-called status lot). Is the basic concept of. After the insulating object has been inserted into the intermediate space or status lot, stator windings are introduced into the intermediate space. In this case, the presence of the insulating body there firstly facilitates the positioning of the stator windings in the individual intermediate spaces. Secondly, it is required for the stator windings, relative to the cooling channel or relative to the coolant flowing through the cooling channel, which is supplied during the operation of the electric machine, ie especially as a heat transfer medium. It is possible to ensure the electric insulation. By this latter means, the waste heat (hereinafter referred to as exhaust heat) generated by the stator winding is filled with plastic in the cooling flow path in which the coolant flowing in the intermediate space and during the operation of the electric machine flows. You can move through. This effect can be improved by choosing a suitable plastic with high thermal conductivity. Plastics typically have electrically insulating properties, thus additionally allowing stator windings located inside an insulating body that is electrically insulated from the stator teeth. In this way, undesired short circuits between the conductor elements of the stator winding are eliminated even if the insulation of the winding is damaged.

The electric machine according to the present invention includes a rotor rotatable about a rotation axis defining an axial direction of the electric machine, and a stator having a conductive stator winding. Further, the electric machine includes at least one cooling passage through which a coolant for cooling the stator windings can flow. In this case, the stator has stator teeth that extend in the axial direction and are spaced from each other along the outer peripheral direction of the rotor. The stator teeth project preferably radially inward from the stator body of the stator and support the stator windings. The intermediate space is in each case formed between two circumferentially adjacent stator teeth. According to the invention, the insulating object is arranged or housed in at least one intermediate space. Such insulating bodies are preferably arranged in a plurality of intermediate spaces of the stator, particularly preferably in all intermediate spaces. The insulating body includes an outer wall made of plastic that partially defines the inside of the body. Preferably, the plastic is realized to be electrically insulating. Further, the plastic may also be used for heat transfer. At least one winding zone containing the stator windings and at least one flow passage zone containing the cooling flow passages are present inside the body of the insulating body. According to the invention, the stator windings are arranged in at least one winding zone in the insulating body. Similarly, the cooling channels through which the coolant flows are arranged in at least one channel zone in the insulating body.

In a preferred embodiment, the insulating body has at least one separating wall of plastic, preferably of electrically insulating plastic. The at least one separating wall divides the interior of the body of the insulating body into at least one winding zone and at least one flow passage zone. After the insulating object is mounted in the status lot and during the assembly process of the stator, the stator windings are placed in the winding zone of the insulating object and the cooling channels are placed in the flow zone of the insulating object. To be done. Thus, in this way, even if the insulation of the stator winding is damaged, undesired short circuits between the stator winding and the cooling channels with the coolant are eliminated.

In a further preferred development, the two flow channel zones containing the first cooling flow channel and the second cooling flow channel are provided inside the body of the insulating object. In this development, at least one winding zone is arranged between two flow passage zones (in a cross section perpendicular to the axial direction), and two separating walls separate these two flow passage zones from each other. To be separated. Such a geometry associated with the two cooling passages of the stator winding allows the transfer of exhaust heat from the stator winding to the cooling passages on either side. In this way, a particularly intensive cooling of the stator winding is achieved.

In a further advantageous development, two winding zones are provided instead of just one winding zone. The two winding zones are arranged adjacent to each other in a cross section perpendicular to the axial direction. In this advantageous development, the winding zones are separated from each other by a phase insulation made of plastic. In this way, unwanted short circuits between conductor elements arranged in two different winding zones are eliminated. This is especially true if electrically insulating plastic is chosen as the material for the separating wall. This allows the placement of the conductor elements in two winding zones that can be connected to different electrical phases of the power supply so that they are electrically isolated from each other. This is necessary, for example, if the electric machine may be operated as a two-phase machine.

Conveniently, the phase isolation may be formed by a further separating wall of the insulating body. It is particularly preferred that the separating wall is formed on the outer wall of the insulating body by a uniform material, and even integrally. This variant has a particularly low manufacturing cost.

In a preferred embodiment, the outer wall and the at least one separating wall extend axially. In this embodiment, the at least one winding zone and the at least one flow passage zone are arranged adjacent to each other in a cross section perpendicular to the axial direction. This allows the stator windings and the cooling channels for cooling the stator windings to be arranged directly adjacent to each other. In this way, a particularly effective heat transfer from the stator windings to the cooling channels is achieved. At the same time, this separating wall ensures the desired electrical insulation between the stator windings and the cooling channels.

Conveniently, the insulating body may be of parallelepiped shape. In a cross section perpendicular to the axial direction, the insulating body may likewise be expediently quadrilateral, preferably rectangular. By this means, the insulating body is provided during the assembly process of the stator in the electric machine, typically in a shape that matches the shape of the status lot into which the insulating body is inserted. Other shapes are possible in various variants. That is to say, in the case of such an alternative shape, the latter shape particularly preferably corresponds substantially to the shape associated with the status lot in which the insulating object is inserted.

In another advantageous development, the anchorage may be formed at the axial end of the insulating body on at least one outer wall in the axial direction. Such an anchoring facilitates the insertion of insulating objects into the individual intermediate spaces along the axial direction. In particular, the correct axial positioning of the insulating body in the intermediate space is ensured.

In a particularly preferred development, the anchorage may be embodied in the form of a wall collar that projects outwards, as it can be realized in a technically simple manner. The abutment is preferably integrally formed on at least one outer wall of the insulating body. This embodiment leads to a particularly low manufacturing cost.

In an advantageous embodiment, the space structure is provided on at least two outer walls by the outer walls being insertable at predetermined intervals into the status lot in the stator of the electric machine. In this way, the insertion of insulating objects into the individual intermediate spaces forming the status lot is facilitated. The insulating object is thus particularly accurately positioned, especially in the intermediate space. A gap between the outer wall and the stator tooth and/or the stator body or both (synonymous with "stator tooth and/or stator body"), ie from two stator teeth, or from the stator body, or both. The potential for voids created by the spaced-apart insulation body may be filled with a heat transfer layer made of plastic that facilitates the transfer of heat to the coolant flowing through the cooling channels.

Particularly preferably, the spatial structure is formed by protrusions which are arranged outside the individual outer walls, away from the interior of the body. This embodiment is technically very easy to implement and leads to advantageous costs during manufacturing.

In an advantageous development, the protrusion may be integrally formed on the outer wall. This embodiment also proves to be particularly cost-effective.

Conveniently, the insulating body may be an injection molded part. Such injection-molded parts are technically simple to manufacture and can therefore be produced in a particularly cost-effective manner in particularly large quantities. Alternatively or additionally, the insulating body may be a monolithic body. Similarly, this has a beneficial effect on manufacturing costs. Alternatively or additionally, the insulating body may be an extruded body.

In a preferred embodiment, the insulating body is inserted in the intermediate space. Such insertion of insulating bodies into the intermediate spaces simplifies the mounting of prefabricated insulating bodies in the individual intermediate spaces and thus simplifies the assembly of the stator of the electric machine.

Conveniently, the axial direction of the insulating object extends parallel to the axial direction of the electric machine.

Particularly advantageously, the insulating body arranged in the intermediate space extends over the entire length of the intermediate space, measured along the axial direction of the electric machine.

Particularly preferably, the insulating body comprises, in a cross section perpendicular to the axial direction, two flow passage zones arranged at the radially inner and radially outer ends of the intermediate space. In this variant, the first cooling channels are arranged in the first channel zone and the second cooling channels are arranged in the second channel zone. In this way, sufficient structural space is available for accommodating the stator winding with a large number of conductor elements in one area between the two flow path zones or between the ends. At the same time, effective cooling of these stator windings is ensured by the two cooling channels.

Conveniently, the first flow passage zone with the first cooling flow passage may be arranged at a radially inner end of the intermediate space, and the second flow passage zone with the second cooling flow passage may be arranged in the intermediate space. May be arranged at the outer end in the radial direction. In the radial direction, the stator windings are arranged between two cooling passages, so that effective heat transfer from the stator windings to the coolant flowing in the two cooling passages is possible. ..

Preferably, the at least one winding zone is arranged along the radial direction of the stator between the two flow passage zones. Particularly preferably, both winding zones, that is to say the first winding zone and the second winding zone, are arranged along the radial direction, preferably directly following one another between the two flow passage zones. Therefore, in this variant, the first flow zone, the first winding zone, the second winding zone and the second flow zone are arranged successively from the radially inner side to the radially outer side.

In a further advantageous development, the insulating body comprises two winding zones arranged next to one another in a cross section perpendicular to the axial direction. In this development, the two winding zones are separated from each other by a phase insulation made of plastic. This makes it possible to arrange the conductor elements of the stator windings provided in the intermediate space in two winding zones which are to be connected to different electrical phases of the power supply. This is required if the electric machine is going to be operated as a two-phase machine.

In another preferred embodiment, the stator winding is part of the distribution winding. In this modification, the insulating body is formed so as to be opened inward in the radial direction, that is, toward the opening of the intermediate space or the opening of the status lot. Therefore, the outer wall corresponding to the insulating object can be omitted.

In an advantageous development, the stator winding comprises a first conductor element and a second conductor element. In this development, the first conductor elements are arranged in the first winding zone and electrically connected to each other for connection with the first in-phase of the power supply. Similarly, in this development the second conductor elements are arranged in the second winding zone and electrically connected to each other for connection with the second in-phase of the power supply. This makes it possible to operate the electric machine as a two-phase electric machine with high operational reliability.

Particularly preferably, in a cross section perpendicular to the axial direction, at least one first and/or second conductor element in the stator windings arranged in the intermediate space is surrounded by plastic. It is particularly preferred to apply this to all first and/or second conductor elements in the stator winding. In this way it is ensured that an undesired short circuit of the stator winding with the coolant flowing through the cooling channel does not occur.

Conveniently, the first conductor element or the second conductor element or both may be formed as a winding bar of electrically conductive material. Particularly preferably, these conductor elements are formed by a mechanically rigid body, and such a form of the conductor element as a winding bar, in particular a construction made of mechanically rigid material, is provided during assembly of the electric machine. Facilitates the introduction of the conductor element into an insulating body arranged in the intermediate space of the stator.

In a further preferred embodiment, at least one, and preferably all winding bars having a rectangular shape with two narrow and two wide sides in a cross section perpendicular to the axial direction saves in particular its structural space. Prove that it is a space.

Particularly preferably, the first conductor element is electrically insulated from the second conductor element by phase insulation. This avoids undesired short circuits between the two conductor elements which are or are about to be connected to different electrical phases of the power supply.

In a further advantageous development, a first heat transfer layer of plastic is arranged between the stator winding and the insulating body. In this way, the dissipation of heat from the stator winding is improved. In particular, undesired constructions, including vacancies or entrained air that reduce the dissipation of heat from the stator windings, can be avoided.

Furthermore, the first heat transfer layer may be arranged between at least two adjacent conductor elements. In this way, unwanted short circuits between two adjacent conductor elements can be prevented.

In a further preferred embodiment, the second heat transfer layer made of plastic is arranged between the cooling channel and the insulating body. This improves the transfer of heat to the cooling channel or the coolant flowing through the cooling channel. In particular, undesired formation of vacancies or entrained air, which reduces the transfer of heat to the cooling channels, can be avoided.

Instead of or in addition to the first heat transfer layer and/or the second heat transfer layer, a third heat transfer layer of plastic is provided between the insulating body and the stator body with two adjacent stator teeth. May be located at. In this way, the dissipation of heat from the stator teeth or from the stator body is improved. In particular, undesired configurations, which include holes or entrained air that reduce the transfer of heat from the stator winding teeth or from the stator body, can be avoided.

Conveniently, the first conductor elements may be arranged in the radially inner winding zone and may be electrically connected to each other for connection with the first in-phase of the power supply. In this variant, the second conductor elements may be arranged in the radially outer winding zone and may be electrically connected to each other for connection with the second in-phase of the power supply. This modification allows the electric machine to be realized or operated as a two-phase machine, which requires only small structural space. In particular, a large number of conductor elements of the stator winding may be arranged in this way in individual intermediate spaces which improve the performance of the electric machine.

In a further preferred embodiment, at least one first conductor element or second conductor element or both, preferably all first conductor elements or second conductor elements or both, in a cross section perpendicular to the axial direction, Surrounded by plastic. In this way, the electrical insulation of the conductor elements is further improved, especially for the cooling channels.

Conveniently, the spatial structure of the insulating body may be supported on the stator teeth and, alternatively or additionally, on the stator body. In this way, the insulating body is mechanically fixed in the intermediate space.

In a further advantageous development, the support structure may be provided on the surface of the two stator teeth or the stator body or both facing the intermediate space. At this time, the outer wall of the insulating object is supported by the support structure. This causes the outer wall to be spaced apart from the stator teeth and/or the stator body, respectively. Therefore, it is easy to insert the insulating objects into the individual intermediate spaces forming the status lot. In particular, the insulating object can thus be positioned very accurately in the intermediate space. Accordingly, in the voids or entrained air between the outer wall and the stator teeth or the stator body or both, the voids or entrained air are spaced from the two stator teeth or from the stator body or both. Voids or entrapped air that may be created by the insulating body may be filled with a heat transfer layer made of plastic. This results in an improved transfer of the heat generated in the stator teeth and the stator body during operation of the electric machine to the coolant flowing through the cooling channels.

Conveniently, the support structure is formed by protrusions which respectively project into the intermediate space from the stator teeth and/or from the stator body. This embodiment is technically very easy to implement and therefore has a cost advantage in manufacturing.

In an advantageous development, the projections are respectively formed integrally with the stator tooth or the stator body or both. This embodiment proves particularly cost-effective.

In another preferred embodiment, an additional cooling channel is formed in the stator body, in particular in a region of the stator body between two stator teeth which define an intermediate space. Such additional cooling channels may be implemented, for example, in the form of through holes or holes in the individual stator bodies. Particularly preferably, the additional cooling passage defines an outer intermediate space in the radial direction and is arranged in a region of the stator body adjacent to the intermediate space radially inward from the intermediate space. In this way, an additional cooling effect in the intermediate space may occur in connection with improved heat dissipation from the stator windings arranged in said intermediate space.

In another preferred embodiment, the plastic constituting the first heat transfer layer is formed by a preferably electrically insulating first plastic material. Alternatively or additionally, in this embodiment, the plastic forming the second heat transfer layer may be formed by a second plastic material, which is preferably electrically insulating. Alternatively or additionally, in this embodiment, the plastic forming the third heat transfer layer may be formed by a third plastic material, which is preferably electrically insulating. Alternatively or additionally, in this embodiment the plastic forming the insulating body, in particular the plastic forming the outer wall of the insulating body, is preferably formed by a fourth plastic material which is electrically insulating. Good.

Conveniently, at least one of the first plastic material, the second plastic material, the third plastic material and the fourth plastic material may be thermoplastic. Alternatively or additionally, at least one of the first plastic material, the second plastic material, the third plastic material and the fourth plastic material may be thermosetting. In this case, the thermal conductivity of both the thermosetting plastic and the thermoplastic can be set by selecting the material composition. Therefore, the thermal conductivity of thermoplastics is greater than or equal to that of thermosetting plastics, and vice versa. The use of thermoplastics has various advantages over the use of thermosets. By way of example, thermoplastics show better recyclability compared to thermosetting plastics due to the application of a reversible molding process during their processing, and also have low brittleness and improved damping properties. .. However, since thermoplastics are usually more expensive to manufacture than thermosets, the selective use of thermoplastics is recommended. The use of thermoset plastics set in these fields and having a reduced thermal conductivity, which are considered insignificant in terms of heat transfer, leads to a reduction in the manufacturing costs of the electric machine.

Advantageously, at least two of the first plastic material, the second plastic material, the third plastic material and the fourth plastic material have the same thermal conductivity. Alternatively or additionally, at least one of the first plastic material, the second plastic material, the third plastic material and the fourth plastic material may have different thermal conductivities.

Conveniently, at least two of the first plastic material, the second plastic material, the third plastic material and the fourth plastic material may be the same material. However, also at least one of the first plastic material, the second plastic material, the third plastic material and the fourth plastic material may be a different material.

Advantageously, the thermal conductivity of said plastic, in particular the thermal conductivity of at least one of the first plastic material, the second plastic material, the third plastic material and the fourth plastic material, is at least 0.5 W/mK, preferably , At least 1 W/mK.

In a particularly preferred embodiment, the stator winding is part of the distribution winding.

The invention also relates to a motor vehicle having the electric machine described above. Therefore, the effects of the electric machine described above can be applied to the motor vehicle according to the present invention.

Further important features and advantages of the invention are apparent from the dependent claims, from the drawings and from the description of the associated figures based on the drawings.

It goes without saying that the features mentioned above and below are not only to be used in the individually indicated combinations, but also in other combinations or in each case without departing from the scope of the invention.

Preferred exemplary embodiments of the invention are illustrated in the drawings and are described in more detail in the description below.

FIG. 1 is an isometric view showing an example of an insulating object according to the present invention. FIG. 2 is a sectional view showing the insulating object of FIG. FIG. 3 is a cross-sectional view showing an example of an electric machine according to the present invention having the insulating object of FIGS. 1 and 2. FIG. 4 is a sectional view of the stator of the electric machine according to FIG. 3 in a direction perpendicular to the rotation axis of the rotor. FIG. 5 is a detailed configuration of the stator of FIG. 4, and is a cross-sectional view showing a region of an intermediate space between two stator teeth adjacent to each other in the outer peripheral direction. FIG. 6 is a cross-sectional view showing a modified example of FIG. FIG. 7 is a cross-sectional view showing another exemplary modification of FIG.

1 and 2 show an example of an insulating object 100 made of plastic 11 according to the invention for a stator of an electric machine. Conveniently, the insulating body 100 is an injection molded part. Further, the insulating body 100 may be a monolithic body, or alternatively or in addition, an extruded body.

1 shows an isometric view of an insulating object 100, and FIG. 2 shows a cross-section view. The insulating object 100 defines a body interior 104 thereof. In FIG. 1, the insulating object 100 has a parallelepiped shape. This parallelepiped shape is formed by four outer walls 101a, 101b, 101c and 101d made of plastic 11. The four outer walls 101a to 101d extend along the axial direction a. As shown in FIG. 2, in the cross section perpendicular to the axial direction a, the outer walls 101a to 101d form two narrow surfaces 102a and 102b and two wide surfaces 103a and 103b. The two narrow surfaces 102a and 102b face each other. Similarly, the two wide surfaces 103a and 103b face each other. The two narrow surfaces 102a and 102b are preferably arranged orthogonal to the two wide surfaces 103a and 103b.

As shown in FIGS. 1 and 2, the main body interior 104 is divided into first winding zone 106a and second winding zone 106 by separating walls 105a, 105b and 105c made of plastic 11, which also extend along the axial direction a. 106b, a first flow passage zone 107a and a second flow passage zone 107b. Therefore, the first separation wall 105a is arranged between the first winding zone 106a and the first flow passage zone 107a. The second separation wall 105b is arranged between the second winding zone 106b and the second flow passage zone 107b.

The third separation wall 105c is arranged between the first winding zone 106a and the second winding zone 106b. In the cross-section shown in FIG. 2, the three separating walls 105a, 105b and 105c in each case run parallel to each other and further to the outer walls 101a, 101b. Therefore, the three separation walls 105a, 105b and 105c extend orthogonally to the two outer walls 101c, 101d.

The two flow passage zones 107a, 107b can be used to individually accommodate a first cooling flow passage and a second cooling flow passage (not shown in FIGS. 1 and 2). Similarly, the two winding zones 106a, 106b can be used to accommodate the conductor elements (not shown in FIGS. 1 and 2) that make up the stator windings.

As is apparent from FIGS. 1 and 2, the two winding zones 106a, 106b are arranged immediately next to each other. The two winding zones 106a, 106b are further arranged between the two flow passage zones 107a, 107b. The two winding zones 106a, 106b are also electrically insulated and spatially separated from each other by a phase insulation 108 made of plastic 11. The phase insulation 108 is formed by the existing separation wall 105c.

According to FIG. 1, the shaft retainer 109 may be formed on the shaft ends 111 of the four outer walls 101 a to 101 d of the insulating object 100.

The axle retainer 109 may be formed as part or all of the outwardly projecting outer peripheral wall collar 110. The outer peripheral wall collar 110 is integrally formed with all four outer walls 101a to 101d of the insulating object 100.

An electric machine 1 including the above-described insulating object 100 will be described with reference to FIGS. 3 and 4. The electric machine 1 has such dimensions that it is used in vehicles, preferably road vehicles. FIG. 3 shows the electric machine 1 with a longitudinal cross section, and FIG. 4 shows its cross section.

The electric machine 1 comprises a rotor 3 which is only shown schematically in FIG. 3 and comprises a stator 2. For the sake of clarity, FIG. 4 shows the stator 2 as a separate view of FIG. 3 along the section line II-II and in a section perpendicular to the axis of rotation D. 3, the rotor 3 includes a rotor shaft 31, and may include a plurality of magnets whose magnetic polarization alternates along the outer peripheral direction U, which is not shown in more detail in FIG. The rotor 3 is rotatable with respect to the rotation axis D, and the position of the rotation axis D is determined by the central long axis M of the rotor shaft 31. The rotation axis D defines an axial direction A extending parallel to the rotation axis D. The radial direction R is perpendicular to the axial direction A. The outer peripheral direction U rotates about the rotation axis D.

As can be seen from FIG. 3, the rotor 3 is arranged in the stator 2. Therefore, the electric machine 1 shown here is a so-called internal rotor. However, when the rotor 3 is arranged outside the stator 2, it may be realized as a so-called external rotor. The rotor shaft 31 is rotatably mounted with respect to the rotation axis D of the stator 2 on a first bearing 32a and a second bearing 32b that is axially spaced from the first bearing 32a.

Moreover, as is known, the stator 2 comprises a plurality of stator windings 6 which are energized to generate a magnetic field. The magnetic interaction between the magnetic field generated by the magnets of the rotor 3 and the magnetic field generated by the conductive stator winding 6 causes the rotor 3 to rotate.

The cross section of FIG. 4 shows that the stator 2 may have a ring-shaped stator body 7 made of, for example, iron. In particular, the stator body 7 may be formed from a plurality of stator body plates (not shown). The stator body plates are stacked on each other along the axial direction A and are bonded to each other. A plurality of stator teeth 8 are integrally formed with the stator body 7 on the radially inner side. The plurality of stator teeth 8 extend in the axial direction A, protrude inward in the radial direction from the stator body 7, and are arranged at intervals from each other in the outer peripheral direction U. Each stator tooth 8 carries a stator winding 6. The individual stator windings 6 together form a winding arrangement. Depending on the number of magnetic poles formed by this stator winding 6, the individual stator windings 6 of all stator winding arrangements may be correspondingly electrically connected together.

During operation of the electric machine 1, the stator windings 6 to which a voltage is applied have to be dissipated from the electric machine 1 in order to prevent overheating and damage thereof and also destruction of the electric machine 1. Occurs. Therefore, the stator winding 6 is cooled by the help of the coolant K that passes through the stator 2 and absorbs the exhaust heat generated in the stator winding 6 by the movement of heat.

In order to pass the coolant K through the stator 2, the electric machine 1 comprises a coolant distribution space 4 into which the coolant K is introduced via the coolant inlet 33. A coolant collecting space 5 is arranged at a distance from the coolant distributing space 4 in the axial direction A. The coolant distribution space 4 is in fluid communication with the coolant collection space 5 by a plurality of cooling channels 10. It can be seen from the representation in FIG. 3 that the cooling channel 10 is only one of them. Although not shown, the coolant distribution space 4 and the coolant collection space 5 may each have a ring shape in a cross section perpendicular to the axial direction A. Along the outer peripheral direction U, the plurality of cooling channels 10 are arranged at intervals. In each case, the cooling channel 10 extends along the axial direction A from the ring-shaped coolant distribution space 4 to the ring-shaped coolant collection space 5. Thus, the coolant K introduced into the coolant distribution space 4 via the coolant inlet 33 may be distributed in the individual cooling channels 10. After flowing through the cooling flow path 10 and absorbing heat from the stator winding 6, the coolant K is collected in the coolant collecting space 5 and again via the coolant outlet 34 provided in the stator 2. , From the electric machine 1 to the outside.

As is clear from FIGS. 3 and 4, the intermediate space 9 is in each case formed between two stator teeth 8 adjacent to each other in the outer peripheral direction U. The intermediate space 9 is also known to those skilled in the art as a so-called "status lot" or "stator groove", which extends in the axial direction A just like the stator teeth 8. An insulating object 100 made of plastic 11 for accommodating the stator winding 6 and the cooling flow passage 10 is inserted into each intermediate space 9. In this case, the insulating body 100 is arranged in each of the intermediate spaces 9 such that its axial direction a extends parallel to the axial direction A of the electric machine 1, ie of the stator 2.

Advantageously, the insulating bodies 100 arranged in the individual intermediate spaces 9 extend along the entire length 1 of the intermediate spaces measured along the axial direction A of the electric machine 1 (see also FIG. 3 in this regard).

The example of FIG. 5 will be described below. That is, a detailed example of the intermediate space 9 embodied between two stator teeth 8 (also referred to as stator teeth 8a and 8b in the following description) adjacent to each other in the outer peripheral direction U is shown. FIG. 5 shows the intermediate space 9 in a cross section perpendicular to the axial direction A.

In FIG. 5, the intermediate space 9 has an opening 52 inside in the radial direction. That is, the intermediate space 9 is formed so that the inner side in the radial direction is open. The intermediate space 9 may have an unequal quadrilateral shape, particularly a rectangular shape, in a cross section perpendicular to the axial direction A. In the cross section, the above quadrilateral shape is applied to the cross sectional shape of the insulating object 100. Particularly advantageously, the intermediate space 9 and the insulating body 100 have the same shape or contour. In the example of FIG. 5, the first cooling flow path 10 is arranged in a region of the intermediate space 9 or the radially inner end 56 a of the status lot 54, that is, a region of the opening 52. Further, the second cooling flow passage 10 is arranged in a region of the radially outer end portion 56b of the intermediate space 9, that is, in the vicinity of the stator body 7 that defines the radially outer side of the intermediate space 9.

As is apparent from FIG. 5, the stator winding 6 arranged in the intermediate space 9 or in the body interior 104 comprises a first conductor element 60a and a second conductor element 60b. The first conductor elements 60a are arranged in the first winding zone 106a of the insulating object 100 and may be electrically connected to each other for connection with a first in-phase of a power supply (not shown). .. This electrical connection may be made axially outside of the intermediate space 9 or the status lot 54. The second conductor elements 60b are arranged in the second winding zone 106b of the insulating object 100 and may be electrically connected to each other for connection with the second in-phase of the power supply. This electrical connection may also be made axially outside the intermediate space 9 or the status lot 54. Therefore, the first conductor element 60a is electrically isolated from the second conductor element 60b by the phase isolation 108.

As shown in FIG. 5, the first conductor element 60a and the second conductor element 60b are in each case configured as winding bars 65a, 65b made of an electrically conductive material, and mechanically because of their bar shape. Is also made rigid. In a cross section perpendicular to the axial direction A, the winding bars 65a, 65b each have a rectangular shape 66 with two narrow surfaces 67 and two wide surfaces 68.

The first flow passage zone 107 a having the first cooling flow passage 10 is arranged at the radially inner end portion 56 a in the intermediate space 9 in the radial direction R. Accordingly, the second flow path zone 107b having the second cooling flow path 10 is arranged at the radially outer end portion 56b of the intermediate space 9 in the radial direction R. Thus, the two winding zones 106a and 106b along the radial direction R are arranged between the two flow passage zones 107a and 107b. Therefore, the first winding zone 106a having the first conductor element 60a follows the first flow passage zone 107a having the first cooling flow passage 10 along the radial direction R from the radial inner side to the radial outer side. .. This first winding zone 106a is followed by a second winding zone 106b with a second conductor element 60b. This time, the second winding zone 106b is followed by the second flow passage zone 107b having the second cooling flow passage 10 along the radial direction R.

Further, as can be seen from FIG. 5, the first heat transfer layer 112a made of the plastic 11 is insulated from the first conductor element 60a or the second conductor element 60b in the stator winding 6 or both in the cross section perpendicular to the axial direction A. It may be arranged between the object 100 and the object 100. As shown in FIG. 5, the first heat transfer layer 112a may also be arranged between the two conductor elements 60a, 60b. Preferably, all the first conductor elements 60a and the second conductor elements 60b are surrounded by the plastic 11 in a cross section perpendicular to the axial direction A.

In place of or in addition to the first heat transfer layer 112a, the (second) heat transfer layer 112b made of the plastic 11 has a cross section perpendicular to the axial direction A and is formed by connecting the individual cooling flow paths 10 and the insulating object 100. It may be arranged in between.

As further apparent from FIG. 5, the space structure 113 is arranged such that the outer walls 101b, 101c and 101d of the insulating object 100 are arranged in an intermediate space 9 spaced from the stator teeth 8a, 8b or the stator body 7 or both. As a result, the outer walls 101b, 101c, and 101d are formed. Spatial structure 113 is conveniently formed by protrusions 114 that are located on the outer surface of the individual outer walls 101b, 101c and 101d, facing outward from the body interior 104 of the insulating object 100. Particularly advantageously, the protrusion 114 may be integrally formed on the individual outer walls 101b, 101c and 101d. In this way, the space structure 113 is supported by the stator teeth 8a, 8b and by the stator body 7. In the simplified variant of this example, the spatial structure 113 may be omitted.

The voids formed between the outer walls 101b, 101c and 101d and the stator teeth 8 or the stator body 7 or both may be filled with the third heat transfer layer 112c made of the plastic 11. The third heat transfer layer 112c made of the plastic 11, which is an alternative or an additional means of the first heat transfer layer 112a or the second heat transfer layer 112b or both of them, has the insulating body 100 in a cross section perpendicular to the axial direction A. And a stator body 7 having two adjacent stator teeth 8a, 8b.

As shown by the dashed line in FIG. 5, a further cooling channel 10 ′ may be formed and arranged in the stator body 7 adjacent to the radially inner side of the intermediate space 9. Such additional cooling channels 10' may be realized in the form of holes or through holes.

FIG. 6 shows an exemplary variant according to FIG. Only the differences between the two variants will be described below. In FIG. 6, the support structure 120 may be formed on the surface of the two stator teeth 8 a and 8 b facing the intermediate space 9 and the surface of the stator body 7. The support structure 120 may support the outer walls 101b, 101c, and 101d of the insulating object 100. Similar to the spatial structure 113 of the insulating body 110, the support structure 120 may be formed in the intermediate space 9 by protrusions 121 projecting from the stator teeth 8a, 8b and/or from the stator body 7. The protrusion 121 of the support structure 120 may be formed integrally with the two stator teeth 8a, 8b or the stator body 7 or both.

FIG. 7 shows a further exemplary variant according to FIG. Only the differences between the two variants will be described below. In the example of FIG. 7, the insulating object 100 has a quadrilateral shape having a non-rectangular interior angle between two adjacent outer walls 101a, 101b, 101c and 101d in a cross section perpendicular to the axial directions a and A, respectively. There is. Furthermore, the stator winding 6 with the flexible conductor element 60c is arranged only in the winding zone 106a. In the example of FIG. 7, the two cooling flow paths 10 are arranged at the first cooling flow path 10 arranged at the radially inner end 56 a of the intermediate space 9 and at the radially outer end 56 b of the intermediate space 9. It is provided in the second cooling flow path 10. Therefore, the first flow path zone 107a of the insulating object 100 having the first flow path 10 is arranged in a region of the radially inner end portion 56a. Accordingly, the second flow path zone 107 b having the second flow path 10 is arranged in a region of the radially outer end portion 56 b of the intermediate space 9. In the modification of FIG. 7, the insulating object 100 is formed so as to be open inward in the radial direction, that is, toward the intermediate space 9 or the opening 52 of the status lot 54. By this means, the outer wall 101a of the insulating object 100 is omitted.

As is clear from FIG. 7, the separation wall 105b is provided only between the winding zone 106a and the second flow passage zone 107b. In contrast, such a separating wall is not provided between the winding zone 106a and the first flow passage zone 107a. In a variant, such a separating wall may also be provided between the winding zone 106a and the first flow passage zone 107a. Accordingly, the separation wall 105b shown in FIG. 7 may be omitted in a further modification. Further combination possibilities are immediately apparent to the person skilled in the art from FIG. 7 and are therefore embodied without an exact description.

In the illustrated scenario, the plastic 11 making up the first heat transfer layer 112a is formed by the electrically insulating first plastic material K1 and the plastic 11 making up the second heat transfer layer 112b is the electrically insulating second plastic material. The plastic 11 formed of K2 and constituting the third heat transfer layer 112c is formed of the electrically insulating third plastic material K3. The plastic 11 forming the insulating body 100, particularly the plastic 11 forming the outer walls 101a to 101d of the insulating body 100 is similarly formed of the electrically insulating fourth plastic material K4.

In the illustration of each figure, the fourth plastic material K4 constituting the insulating object 100 is a thermosetting plastic, while the first plastic material K1 and the second plastic material K1 constituting the three heat transfer layers 112a, 112b and 112c. The plastic material K2 and the third plastic material K3 are thermoplastics. It goes without saying that other variants of thermoplastics and thermosets to the four plastic materials K1, K2, K3 and K4 are possible in various variants in this regard. In the illustrated scenario, the first plastic material K1, the second plastic material K2 and the fourth plastic material K4 each have a higher thermal conductivity than the third plastic material K3. This ensures effective heat transfer from the stator winding 6 to the cooling flow passage 10. In the illustration of each figure, the four plastic materials K1, K2, K3 and K4 are different materials. The thermal conductivity of the four plastic materials K1, K2, K3 and K4 is in this case at least 0.5 W/mK, preferably at least 1 W/mK.

In the following description, FIG. 3 will be referred to again. In FIG. 3, the stator 2 having the stator body 7 and the stator teeth 8 is axially arranged between the first end face shield 25a and the second end face shield 25b.

As is apparent from FIG. 3, a part of the coolant distribution space 4 is arranged in the first end face shield 25a, and a part of the coolant collection space 5 is arranged in the second end face shield 25b. The coolant distribution space 4 and the coolant collection space 5 are thus partly formed by the cavities 41a, 41b provided in the plastic compound 11 in each case. The first cavity 41a is supplemented here by a cavity 42a embodied in the first end face shield 25a forming the coolant distribution space 4. Correspondingly, the second cavity 41b is supplemented by a cavity 42b embodied in the second end face shield 25b forming the coolant collecting space 5. Thus, in a variant of the embodiment described above, the plastic 11 at least partly partitions the coolant distribution space 4 and the coolant collection space 5.

Further, the coolant supply 35 fluidly couples the coolant distribution space 4 to the outside of the first end face shield 25a, as shown in FIG. 3, especially with the coolant inlet 33 provided on its outer peripheral surface. As described above, the first end face shield 25a may be embodied. In response, the coolant discharge 36 fluidically connects the coolant collecting space 5 to the outside of the second end face shield 25b, as shown in FIG. May be embodied in the second end face shield 25b so as to be coupled to. Thereby, in the case where each of the first end portion 14a and/or the second end portion 14b of the stator winding 6 is radially outside, and along the axial direction A, the extension direction of these end portions 14a, 14b. Also, it is possible to arrange the coolant distribution space 4 or the coolant collection space 5 or both. During operation of the electric machine 1, the first end 14a and the second end 14b of the stator winding 6, which are particularly exposed to heat load, are also very effectively cooled by this measure.

According to FIG. 3, the plastic 11 may be arranged on the outer peripheral surface 30 of the stator body 7, and thus the plastic coating 11.1 may be formed on the outer peripheral surface 30. In this way, the stator body 7 of the stator 2, which is typically formed from a conductor stator plate, may be electrically insulated from its surroundings. Therefore, it is not necessary to prepare a separate housing for housing the stator body 7.

Claims (27)

In particular, an electric machine (1) for a motor vehicle, comprising:
A rotor (3) rotating about a rotation axis (D) defining an axial direction (A) of the electric machine (1), and a stator (2) having a conductive stator winding (6),
At least one cooling channel (10) through which a coolant (K) for cooling the stator winding (6) flows,
The stator (2) has stator teeth (8) extending in the axial direction (A) and spaced from each other along the outer peripheral direction (U) of the rotor (3). Teeth (8) preferably project radially inward from the stator body (7) of the stator (2) and support the stator winding (6),
An intermediate space (9) is formed in each case between two stator teeth (8, 8a, 8b) adjacent to said outer circumferential direction U,
An insulating body (100) is arranged in at least one intermediate space (9), the insulating body (100) having outer walls (101a, 101b, 101c, 101d) made of plastic (11), Inside the body (104) provided with at least one winding zone (106a, 106b) containing the winding (6) and at least one flow passage zone (107a, 107b) containing the cooling flow passage (10). )
The stator winding (6) is arranged in at least one of the winding zones (106a, 106b) in the insulating body (100), and the cooling channel (10) is arranged in the insulating body (100). An electric machine arranged in at least one of the flow passage zones (107a, 107b). The electric machine according to claim 1,
Said insulating body (100) has at least one separating wall (105a, 105b, 105c) of said plastic (11), preferably electrically insulating plastic (11),
At least one separation wall (105a, 105b, 105c) defines inside the body (104) at least one winding zone (106a, 106b) and at least one flow passage zone (107a, 107b). An electric machine characterized by further division. The electric machine according to claim 1 or 2,
There are two said flow passage zones (107a, 107b) accommodating a first cooling flow passage (10) and a second cooling flow passage (10),
In a cross section perpendicular to the axial direction (a), at least one said winding zone (106a, 106b) is arranged between two said flow passage zones (107a, 107b) and two separation walls (105a, 105b). ) Is separated from the flow path zone (107a, 107b) by a). The electric machine according to any one of claims 1 to 3,
The two winding zones (106a, 106b) are arranged adjacent to each other in a cross section perpendicular to the axial direction (a),
Electric machine, characterized in that the winding zones (106a, 106b) are separated from each other by a phase insulation (108) made of plastic (11). The electric machine according to claim 4,
An electrical machine characterized in that the phase insulation (108) is formed by a separating wall (105c) consisting of the insulating body (100). The electric machine according to any one of claims 1 to 5,
The insulating body (100) is an injection molded part,
And/or the insulating body (100) is a monolithic body,
And/or the insulating body (100) is an extruded body. The electric machine according to any one of claims 1 to 6,
The insulating body (100) is arranged at each of radially inner and radially outer ends of the intermediate space (9) in a cross section perpendicular to the axial direction (A) of the electric machine (1). Including two said flow passage zones (107a, 107b),
An electric machine characterized in that the first cooling channel is formed in the first channel zone (107a) and the second cooling channel is formed in the second channel zone (107b). The electric machine according to claim 7,
The first flow passage zone (107a) having the first cooling flow passage (10) is arranged at a radially inner end portion (56a) of the intermediate space (9), and the second cooling flow passage (10) is provided. An electric machine characterized in that the second flow path zone (107b) having is arranged at a radially outer end (56b) of the intermediate space (9). The electric machine according to claim 7 or 8,
At least one said winding zone (106a, 106b), preferably both said winding zones (106a, 106b), is provided with two said flow passage zones (107a, 107b) along the radial direction of said stator (2). ) Is located in the electric machine. The electric machine according to any one of claims 1 to 9,
The insulating body (100) comprises two winding zones (106a, 106b) arranged adjacent to each other in a cross section perpendicular to the axial direction (A),
Electric machine, characterized in that the two winding zones (106a, 106b) are separated from each other by a phase insulation (108) made of the plastic (11). The electric machine according to any one of claims 1 to 10,
Electric machine, characterized in that the stator winding (6) is part of a distribution winding. The electric machine according to any one of claims 1 to 11,
The stator winding (6) includes a first conductor element (60a) and a second conductor element (60b),
The first conductor elements (60a) are arranged in the first winding zone (106a) and electrically connected to each other for connection with the first in-phase of the power supply,
The second conductor elements (60b) are arranged in the second winding zone (106b) and are electrically connected to each other for connection with the second in-phase of the power supply. Electric machine. The electric machine according to any one of claims 1 to 12,
An electric machine characterized in that a (first) heat transfer layer (112a) made of the plastic (11) is arranged between the stator winding (6) and the insulating body (100). The electric machine according to claim 13,
The electric machine according to claim 1, wherein the first heat transfer layer (112a) is further present between at least two conductor elements (60a, 60b) arranged adjacent to each other. The electric machine according to any one of claims 1 to 14,
An electric machine characterized in that a (second) heat transfer layer (112b) made of the plastic (11) is arranged between the cooling channel (10) and the insulating body (100). The electric machine according to any one of claims 1 to 15,
The (third) heat transfer layer (112c) made of the plastic (11) has the insulating body (100) and the stator having two stator teeth (8a, 8b) adjacent to each other in the outer peripheral direction (U). An electric machine, characterized in that it is arranged between the body (7). The electric machine according to any one of claims 12 to 16,
First conductor elements (60a) are arranged in said winding zone (106a) radially inside and electrically connected to each other for connection with a first in-phase of the power supply,
A second conductor element (60b) is arranged in the winding zone (106b) radially outside and is electrically connected to each other for connection with a second in-phase of the power supply. And an electric machine. The electric machine according to any one of claims 12 to 17,
An electric machine characterized in that the first conductor element (60a) is electrically insulated from the second conductor element (60b) by phase insulation (108). The electric machine according to any one of claims 1 to 18,
A support structure (120) is provided on the surface of the stator body (7) facing the two stator teeth (8a, 8b) or the intermediate space (9), or both,
The outer walls (101a-101d) of the insulating body (100) are spaced from the stator teeth (8a, 8b) or the stator body (7), or both, respectively. An electric machine, characterized in that it is supported by said support structure (120) so as to be arranged at. The electric machine according to any one of claims 1 to 19,
The support structure (120) is formed by protrusions (121) projecting into the intermediate space 9 from the stator teeth (8a, 8b) or from the stator body (7) or both. A characteristic electric machine. The electric machine according to any one of claims 1 to 20,
The electric machine characterized in that the protruding portion (121) is integrally formed with the stator tooth (8a, 8b) or the stator body (7) or both of them. The electric machine according to any one of claims 1 to 21,
The plastic (11) forming the first heat transfer layer is preferably formed of an electrically insulating first plastic material (K1),
The plastic (11) forming the second heat transfer layer is preferably formed of an electrically insulating second plastic material (K2),
The plastic (11) forming the third heat transfer layer is preferably formed of an electrically insulating third plastic material (K3),
The plastic (11) forming the insulating body (100), particularly the plastic (11) forming the outer walls (101a to 101d), is preferably formed of an electrically insulating fourth plastic material (K4). An electric machine characterized by being. The electric machine according to any one of claims 1 to 22,
At least one of the first plastic material (K1), the second plastic material (K2), the third plastic material (K3) and the fourth plastic material (K4) is a thermoplastic,
At least one of the first plastic material (K1), the second plastic material (K2), the third plastic material (K3), and the fourth plastic material (K4) is a thermosetting plastic. A characteristic electric machine. The electric machine according to any one of claims 1 to 23,
At least two of the first plastic material (K1), the second plastic material (K2), the third plastic material (K3) and the fourth plastic material (K4) have the same thermal conductivity,
And/or at least two of the first plastic material (K1), the second plastic material (K2), the third plastic material (K3) and the fourth plastic material (K4) are preferably all The plastic materials (K1, K2, K3, K4) each have different thermal conductivity,
At least one of the first plastic material (K1), the second plastic material (K2), the third plastic material (K3) and the fourth plastic material (K4) has different thermal conductivities. An electric machine characterized by being present. The electric machine according to any one of claims 1 to 24,
At least two of the first plastic material (K1), the second plastic material (K2), the third plastic material (K3), and the fourth plastic material (K4) are the same material,
And/or at least one of the first plastic material (K1), the second plastic material (K2), the third plastic material (K3) and the fourth plastic material (K4) is a different material. An electric machine characterized by. The electric machine according to any one of claims 1 to 25,
Thermal conductivity of the plastic (11), in particular at least one of the first plastic material (K1), the second plastic material (K2), the third plastic material (K3) and the fourth plastic material (K4). An electric machine characterized in that the degree is at least 0.5 W/mK, preferably at least 1 W/mK. A motor vehicle comprising an electric machine (1) according to any one of claims 1 to 26.